King James Version (KJV)
Because I knew that thou {art} obstinate, and thy neck {is} an iron sinew, and thy brow brass; {obstinate: Heb. hard}
Modern English
Because I knew that you are obstinate, and your neck is an iron sinew, and your brow brass;
Hebrew
מִדַּעְתִּ֕י כִּ֥י קָשֶׁ֖ה אָ֑תָּה וְגִ֤יד בַּרְזֶל֙ עָרְפֶּ֔ךָ וּמִצְחֲךָ֖ נְחוּשָֽׁה׃
midaʿtiy kiy qasheh ʾatah vgiyd barzel ʿarpeka vmiṣḥaka nḥvshah